The present disclosure relates to a vehicular impact-absorbing member. More particularly, the present disclosure relates to a vehicular impact-absorbing member that is configured to absorb a load using a deformability of a wood member.
Such a vehicular impact-absorbing member is taught, for example, by JP2013-44339A. The impact-absorbing member taught by JP2013-44339A has a housing and a substantially rectangular parallelepiped core member made of resin or paper. The core member is combined with the housing. The impact-absorbing member is attached to a vehicle such that a (compression) load or impact can be longitudinally applied to the core member at a longitudinal end surface of the core member. When a vehicular collision occurs, the impact-absorbing member (the core member) may be axially compressed and collapsed by the load applied thereto, so that the load may be absorbed.
Also, such a vehicular impact-absorbing member is taught, for example, by JP2017-7598A. The impact-absorbing member taught by JP2017-7598A is composed of a substantially rectangular parallelepiped wood member (timber). The impact-absorbing member is attached to a vehicle such that a (compression) load or impact can be longitudinally applied to the impact-absorbing member at a longitudinal end surface thereof. When the load is applied to the vehicle due to a vehicular collision, the impact-absorbing member may be axially compressed and collapsed by the load applied thereto, so that the load may be absorbed.
The impact-absorbing member (the wood member) is attached to the vehicle while an axis direction of annual rings thereof is aligned with a direction in which the load is applied. In particular, the impact-absorbing member is positioned between a front member (a bumper reinforcement member) and a side member while the axis direction of annual rings thereof is aligned with a front-back direction of the vehicle. The front member is formed as a rectangular tubular member that is positioned in a front end of the vehicle so as to extend in a widthwise or transverse direction of the vehicle. The front member has a through hole formed in a rear wall thereof and configured to receive a front end of the impact-absorbing member. Conversely, the side member is formed as a rectangular tubular member that is positioned in a front lateral side of the vehicle so as to extend in a longitudinal or front-back direction of the vehicle. The side member has a through bore extending therethrough and configured to receive a rear end of the impact-absorbing member. Further, the impact-absorbing member is formed or processed such that the axis direction of annual rings thereof corresponds to a longitudinal direction thereof. The impact-absorbing member is positioned between the front member and the side member while the front and rear ends thereof are respectively inserted into the through hole of the front member and the through bore of the side member. The impact-absorbing member thus positioned is fixed to the front and side members by bolting. Thus, the impact-absorbing member is attached to the vehicle while the axis direction of annual rings thereof is aligned with the front-back direction of the vehicle.
The impact-absorbing member thus attached is not completely covered by the front and side members. That is, the impact-absorbing member is substantially exposed over the entire surfaces (upper, lower and side surfaces) except for the front and rear ends thereof that are respectively connected to the front and side members. When an impact or load is applied to the front member due to the vehicular collision, the impact-absorbing member may be axially compressed and deformed by the load applied thereto via the front member, so as to absorb the impact.
However, an excessively high load may be sometimes applied to the impact-absorbing member. Also, the load may be sometimes excessively quickly applied to the impact-absorbing member. Under such conditions, the impact-absorbing member may be cracked in the axis direction of annual rings thereof (the front-back direction of the vehicle). The cracked impact-absorbing member may be broken before it is sufficiently compressed and deformed. This may lead to reduction in impact absorbing characteristics.
In order to solve the problem, the impact-absorbing member may be increased in size. Alternatively, the impact-absorbing member may be covered by hard covering materials. However, the impact-absorbing member increased in size or covered by the hard covering materials may be prohibited from being smoothly compressed or deformed when the load is applied thereto.
Thus, there is a need in the art to provide an improved vehicular impact-absorbing member.